Urothelial abnormalities in the obstructed bladder.

Bladder mucosa from patients undergoing prostatectomy was examined histologically for evidence of pre-malignant change. The mucosal appearances were compared with tissue taken from control patients without bladder outlet obstruction. The appearances in patients with uncomplicated obstruction and in control patients were found to be similar and dysplastic change was uncommon. However, dysplasia was found relatively frequently in patients with bladder outlet obstruction complicated by the presence of infection, catheters or stones. In all, 10 out of 74 patients were found to have dysplasia and 7 of these agreed to have a further cystoscopy and biopsy taken at an interval of between 10 and 28 months after the first examination. Persistent dysplasia was found in all 7 cases and in 3 of these it had progressed from mild to moderate in severity. The significance of these findings is discussed.